1. Field of the Invention
The present invention relates to a visible light communication system and method for use thereof, and more particularly to an improved visible light communication system and method for reducing influence of a propagation characteristic on a light propagation path and improving transmission quality.
2. Description of the Related Art
Recent light communication technology uses light in a visible region, especially for light emitting devices such as a Light Emitting Diode (LED) to achieve a more convenient and higher-rate data communication using an infrastructure of a lighting device installed inside or outside of a building.
Considering the influence on a human body or on a medical device, the LED is the strongest candidate for a light emitting means for high rate optical data communication. Meanwhile, a semiconductor light emitting device, such as a Laser Diode (LD) or a Super Luminescent Diode (SLD), which responds at a higher rate, can also be a candidate. The data transmission rate for optical communication depends on a response speed of the light emitting device. Accordingly, high response speeds of the light emitting device have been noted. In order to further improve the data transmission rate, technology for stably transmitting more data in a single signal that is emitted by the light emitting device is required.
In regard to the aforementioned optical communication technology, for example, Japanese Patent Publication No. 2003-318836 discloses multiple signals being determined according to a light emitting power of multiple LEDs emitting three colors, Red, Green, and Blue, of light (“RGB”) and input data is assigned based on multiple numbers, so that the communication is efficiently performed while maintaining a white color. Further, Japanese Patent Publication No. 2007-166526 discloses a correction frame inserted in a two-dimensional transmission/reception cell to reduce the influence of a background light or a noise.
However, such conventional technologies do not allow a multiplicity that is larger than the number of light sources and limit the achievable high speed of the data transmission. Further, the transmission quality is greatly deteriorated due to the reduction of a luminescence amount in a propagation path, the mixing of ambient light, a light emitting property of a light source, and a color separation sensitivity of a light receiving device.
The present invention addresses the above-mentioned problems and provides a visible light communication system and method to reduce the influence of a propagation characteristic in a light propagation path and improve a transmission quality.